In addition, the staff is available for consulting at any point in the process of using the services. Considerable time is spent discussing experimental design and providing guidance on processes that they themselves are or will be carrying out. They also train investigators in techniques such as superovulating, mating and collecting reproductive tracts from female mice for embryo cryopreservation, isolating DNA for pronuclear micronjections, mouse handling and breeding protocols and cutting tails and genomic DNA preparation Southern blotting to identify correctly mutated ES cells.